This invention relates to a device, particularly a kit for the production of an osteosynthesis implant.
Devices known as osteosynthesis or bone plates are commonly used for fracture fixation, generally with the possibility of a longitudinal adjustment of an osteotomy, as is known, for example, from DE 40 07 306 C and U.S. Pat. No. 5,129,903. In principle, with bone fractures there is a problem with fixing the bone parts together and precisely adjusting their location. With other indications, a bone is initially fractured in a targeted fashion, to subsequently fix the two bone parts together at their point of separation (osteotomy) at a fixed or variable distance so that the bone parts have the opportunity of growing together again.
The known osteosynthesis plates consist of two plate parts, longitudinally displaceable in relation to each other, that can be fixed to the bone parts, for example by means of bone screws. The mechanical guidance with the known osteosynthesis plates is provided by a dove tail guide members. An extracorporeally operable drive mechanism is provided in this area with which the plate parts can be displaced longitudinally to each other. In addition, the drive mechanism is formed such that a shaft, for example, is of a length and orientation such that it passes through the skin of the patient at only one single site after implantation in the patient's body. The shaft can then be operated from the outside using a suitable tool, for example, a screwdriver such that the osteotomy can be lengthened or shortened.
The known osteosynthesis plates sometimes do not provide satisfactory results, particularly when used in the jaw and skull area. Based on their design, the known osteosynthesis plates are spread relatively wide, i.e., their spatial depth is relatively large. This is attributable to the construction of the mechanical guide, for example as a dove tail guide. This can lead to difficulties with the implantation in the case of a spatially narrow area, as dictated by nature, at the implantation site.
With the osteosynthesis plate according to DE 195 42 064 C, an attempt is made to create a design that has significantly smaller dimensions so that it can be used at spatially narrow implantation sites, e.g., in the jaw or skull area.
Forming the mechanical guide from two cylindrical pins oriented in the direction of longitudinal displacement and formed from the first part of the plate and two cylindrical holes oriented in the direction of longitudinal displacement and provided in the second part of the plate has been proposed, where the pins are fitted into the holes.
The known osteosynthesis plates therefore are concerned primarily with the longitudinal displaceability of an osteotomy. They can be used on osteotomies or fractures of relatively large long bones. Use on smaller bones, for example, in the foot area, is practically impossible due to their still substantial overall size. In addition, they often create an unstable system, from the mechanical point of view, with unpredictable bending moments that can have a fatiguing effect on the material of the osteosynthesis plates and unpredictable forces that affect the bone screws used for fixing the plates.